The purpose of the present study is to optimize the cultivation conditions for the productivities of chlorophyll and carotenoid of the microalga chlorellafusca in a flow bioreactor. The effects of CO2 concentration in...The purpose of the present study is to optimize the cultivation conditions for the productivities of chlorophyll and carotenoid of the microalga chlorellafusca in a flow bioreactor. The effects of CO2 concentration in aeration and light intensity as the culture condition were firstly examined. After the cultivation conditions as to CO2 concentration and light intensity were determined, the effects of the concentrations of KNO3, CH3COONa, NaC1 and MgSO4 in the culture medium on the chlorophyll biosynthesis and carotenoid accumulation ofC. fusca were examined. KNO3 and CH3COONa were used as the nitrogen and the organic carbon sources, respectively. They are very important nutrient sources to the microalgae. In fact, when the concentration of the nutrient sources was increased, the syntheses of chlorophyll and the carotenoid accumulation of the microalgae were promoted. Cfusca can take an organic carbon as the nutrient sources for its own growth, so the cell is activated compared to the case only in an inorganic nourishment sources. Mg2＋ is known as a raw material of chlorophyll and it can promote carotenoid accumulation. However, when it exists in excessive quantity, the microalgae receive a stress and it was difficult for microalgae to uptake such nutrient sources. In this study, it was found that there existed the optimum amounts of KNO3, CH3COONa, NaCI and MgSO4 which should be added to the culture medium.展开更多
The effects of direct extracts of compost (DEC), aerated fermentation extracts of compost (AFEC) and non-aerated fermentation extracts of compost (NAFEC) on cucumber growth and the action mechanisms were evaluated bas...The effects of direct extracts of compost (DEC), aerated fermentation extracts of compost (AFEC) and non-aerated fermentation extracts of compost (NAFEC) on cucumber growth and the action mechanisms were evaluated based on the structure and activity analysis of humic-like substances. AFEC increased cucumber growth most significantly, followed by DEC and NAFEC, which was insignificant compared to the control treatment. Humic-like substances from compost extracts played an important role in promoting cucumber growth. Application of humic-like substances stimulated auxin-like activity and increased chlorophyll content and nitrogen accumulation in plants. The positive auxin-like activity of humic-like substances could be attributed to the relative distribution of special carbon groups, such as those with a large amount of peptidic and carbohydratic groups or with a low content of phenolic groups. In conclusion, the best growth promotion by application of AFEC was mainly attributed to the humic-like substances in the AFEC.展开更多
文摘The purpose of the present study is to optimize the cultivation conditions for the productivities of chlorophyll and carotenoid of the microalga chlorellafusca in a flow bioreactor. The effects of CO2 concentration in aeration and light intensity as the culture condition were firstly examined. After the cultivation conditions as to CO2 concentration and light intensity were determined, the effects of the concentrations of KNO3, CH3COONa, NaC1 and MgSO4 in the culture medium on the chlorophyll biosynthesis and carotenoid accumulation ofC. fusca were examined. KNO3 and CH3COONa were used as the nitrogen and the organic carbon sources, respectively. They are very important nutrient sources to the microalgae. In fact, when the concentration of the nutrient sources was increased, the syntheses of chlorophyll and the carotenoid accumulation of the microalgae were promoted. Cfusca can take an organic carbon as the nutrient sources for its own growth, so the cell is activated compared to the case only in an inorganic nourishment sources. Mg2＋ is known as a raw material of chlorophyll and it can promote carotenoid accumulation. However, when it exists in excessive quantity, the microalgae receive a stress and it was difficult for microalgae to uptake such nutrient sources. In this study, it was found that there existed the optimum amounts of KNO3, CH3COONa, NaCI and MgSO4 which should be added to the culture medium.
基金Supported by the Ministry of Agriculture Public Benefit Research Foundation of China (No. 201103004)the National Key Technology R&D Program of China (No. 2010AA10Z401)
文摘The effects of direct extracts of compost (DEC), aerated fermentation extracts of compost (AFEC) and non-aerated fermentation extracts of compost (NAFEC) on cucumber growth and the action mechanisms were evaluated based on the structure and activity analysis of humic-like substances. AFEC increased cucumber growth most significantly, followed by DEC and NAFEC, which was insignificant compared to the control treatment. Humic-like substances from compost extracts played an important role in promoting cucumber growth. Application of humic-like substances stimulated auxin-like activity and increased chlorophyll content and nitrogen accumulation in plants. The positive auxin-like activity of humic-like substances could be attributed to the relative distribution of special carbon groups, such as those with a large amount of peptidic and carbohydratic groups or with a low content of phenolic groups. In conclusion, the best growth promotion by application of AFEC was mainly attributed to the humic-like substances in the AFEC.
